JPH012316A - Plasma CVD equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a plasma CVD apparatus.

(Prior Art) Plasma CVD is generally applied to thin film formation in the manufacturing process of semiconductor devices. There are two types of plasma CVD methods: one that applies a plasma reaction using high-frequency discharge and the other that uses a plasma reaction that uses microwave discharge. The former is used from the standpoint of stability. FIG. 1 shows an example of the former manufacturing apparatus, which has an airtight container (1), both sides (2a) and (2b) of which are airtightly connected to a tunnel (3). The above-mentioned both sides (2a) and (2b) can be opened and closed freely, and when opened, the airtight container (1) is moved into the tunnel (
3). Therefore, guide rails (not shown) are laid at the bottoms of both. Also,
Inside the airtight container (1), an electrode part (4) is connected to a gas supply pipe (
5a) and (5b). As shown in FIG. 2, this electrode part (4) has a main body (8) that forms two adjacent spaces (7a) and (7b) by a partition part (6), and a plurality of parts that close these spaces and Intermediate diffusion plates (LOA), (10b) (not shown) in which flow paths (9) are bored, and insulators (11a),
Diffusion plates (13a) and (13b) (not shown), which are attached through (1lb) (not shown) and have flow paths (12) more densely drilled than the flow path (9), and serve as electrodes. It consists of A cart (14) is mounted on the guide rail (not shown). This cart (14) has holders (15a) and (15b) facing the diffusion plates (13a) and (13b) at a predetermined distance.
) are erected facing each other. These holders are formed with rectangularly cut mounting portions (lea) and (16b), and the substrate (18) is held by a mounting tool (■9) via a back plate (17). On the other hand, the gas supply pipe (
5a) and (5b) are space parts (7a) and (7
b) and is commonly connected to the on-off valve (20). Three flow rate regulators (21), (22), and (23) are connected in parallel to this on-off valve via other piping systems, and each of these has three types of reaction gas supply devices (24). , (25) and (2B) are connected. The diffusion plates (13a) and (13b) are connected to a high frequency power source (not shown), and a high-performance vacuum pump (30) is connected to the airtight container (1) through another piping system. ing.

With the above configuration, the cart (14) holding the board (18)
enters the airtight container (1), and both sides (2a) and (2b
) is closed, the airtight container (1) is moved to a vacuum pump (30)
The pressure is reduced to about lo-4 to 10 Torr. Next, the on-off valve (20) was opened and the predetermined mixture ratio was set to 3.
After supplying seed auxiliary gas to the inside of the airtight container (1) until the pressure reaches about 0.4 Torr, the diffusion plates (13a), (13
b) A high frequency current is applied for a predetermined period of time to form a thin film on the substrate (18). During the above application, the gas supply pipe (5a), (
A predetermined amount of reaction gas is supplied from step 5b), and the vacuum pump is operated to exhaust the supplied gas amount.

(Problems to be Solved by the Invention) A thin film is formed on a substrate, and a film is also formed on a surface other than the substrate. Among these films, the films formed in the channels (9) and (12) caused the following problems. That is,
Since the diffuser plate and the like are fixed in place, the film gradually accumulates as production progresses, making it easy to peel off. Therefore, as mentioned above, the reactant gas introduced in a high vacuum passes through the channels (9) and (12) at a rapid rate, so that the film in the deposited state falls off with its momentum, and the opposing substrate (18) as dust. Needless to say, this adhered substrate was rejected as a defective product.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an apparatus for supplying a reaction gas so that a film formed in a flow path does not fall off.

[Structure of the Invention] (Means for Solving the Problems) An electrode portion having a space for introducing a reaction gas and forming a diffusion hole for diffusing the introduced reaction gas outside the space, and a film forming process. A holder for attaching a substrate to be subjected to the reaction so as to face the diffusion hole, a gas supply device for supplying a reaction gas to the space via an on-off valve, an airtight container for housing the electrode section and the holder, and an airtight container for accommodating the electrode section and the holder. In a plasma CVD apparatus equipped with a pressure reducing device that reduces the pressure of the gas and a power source that generates discharge in the electrode section, a plasma CVD device that branches from the piping between the opening/closing valve and the gas supply device and enters the airtight container via a pressure regulating valve. This configuration is advantageous in that it includes a means for supplying a reaction gas and a control section that opens and closes either the opening/closing valve or the pressure regulating valve.

(Function) Gas is supplied to parts unrelated to the substrate surface during high vacuum, and the gas is quantitatively supplied from the flow channel in a pressure-regulated state after supply, so that The force of the gas weakened and the film no longer fell off.

(Example) EMBODIMENT OF THE INVENTION Hereinafter, this invention will be explained based on drawing which shows an Example.

Note that parts common to those in FIG. 2 are denoted by the same reference numerals, and explanations thereof will be omitted. That is, as shown in FIG. 1, the difference from the conventional device shown in FIG. 2 is that the holder (15a),
(15b) has a pair of supply nozzles (3
5a) and (35b) are provided so that the reaction gas is blown out near the back plate (17).

These supply nozzles include an on-off valve (20) and a flow rate regulator (21).
), (22), and (23) are commonly connected to a branch pipe (3B) branched from the piping system between them. Branch pipe (
A solenoid valve (37) is connected to the middle part of 36).

This solenoid valve (37) is provided in the airtight container (1), and is opened and closed by a control unit (39) that inputs a signal converted from a set predetermined pressure into an electric signal and outputs a control signal. It has become. On the other hand, the on-off valve (20) is opened only during film formation when the solenoid valve (37) is closed.

Next, thin film formation using the above configuration will be explained. 10 to 10”-5TOR by vacuum pump (30)
The process until the pressure is reduced to about R is the same as in the conventional example, but after the pressure is reduced to this pressure, the solenoid valve (37) is opened in response to a signal from the control section (39), and the reaction gas is supplied to the supply nozzle (35a).
.

(35b) is supplied into the airtight container (1) only. Here, if the pressure detector (38) is set in advance to emit a signal at 10-1 Torr, the solenoid valve (37) will close when this pressure is reached, and the supply valve (20) will open. The vacuum pump (30) is operated to supply a predetermined amount of reaction gas from the channels (9) and (12), and exhaust the supplied amount. The above supply and exhaust are continued for a predetermined time and the substrate (1
A film is formed for 8).

In addition, in the above embodiment, the supply nozzles (35a) and (3
Although the air outlet 5b) was provided near the back plate (17), it is not limited thereto and may be installed at other locations.

[Effects of the Invention] During pressure adjustment from high vacuum to low vacuum, the reaction gas is not directly injected onto the substrate through a diffusion plate, that is, a flow path in which a film is formed, but instead is sprayed onto parts unrelated to film formation on the substrate. Since the reaction gas is supplied to the flow path, the phenomenon of film falling off in the flow path is eliminated, and the conventional problem of forming a thin film while the fallen film remains attached as dust is solved, and the film is uniformly formed in a clean state. The film was deposited on

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing a conventional example, and FIG. 3 is a sectional view of an electrode section. (1) ... Airtight container (4) ... Electrode part (5a), (5b) ... Gas supply pipe (9), (1
2)...Flow path (15a), (15b)...φ holder (20)...
On-off valve (35a), (35b) supply nozzle (37)...
solenoid valve

Claims (1)

[Claims] A holder for attaching an electrode part having a space for introducing a reaction gas and a diffusion hole for diffusing the introduced reaction gas out of the space, and a substrate to be subjected to a film forming process so as to face the diffusion hole. a gas supply device that supplies reaction gas to the space via an on-off valve; an airtight container that houses the electrode section and the holder; a pressure reducing device that reduces the pressure inside the airtight container; and a power source that causes discharge in the electrode section. a plasma CVD apparatus comprising: a means for supplying a reaction gas into the airtight container via a pressure regulating valve branched from piping between the on-off valve and the gas supply device; and the on-off valve and the pressure regulating valve. A plasma CVD apparatus comprising: a control section for opening and closing either one of the above.